From mboxrd@z Thu Jan  1 00:00:00 1970
From: jgunthorpe@obsidianresearch.com (Jason Gunthorpe)
Date: Mon, 29 Jul 2013 12:40:48 -0600
Subject: DT bindings as ABI [was: Do we have people interested in device
 tree janitoring / cleanup?]
In-Reply-To: <20130729181607.GM24642@n2100.arm.linux.org.uk>
References: <20130725175702.GC22291@e106331-lin.cambridge.arm.com>
 <51F168FC.9070906@wwwdotorg.org>
 <20130725182920.GA24955@e106331-lin.cambridge.arm.com>
 <20130725184834.GA8296@netboy>
 <20130725213753.GC17616@obsidianresearch.com>
 <20130726045433.GB4100@netboy>
 <20130726171524.GB28895@obsidianresearch.com>
 <20130727084825.GA4707@netboy>
 <20130729175400.GB15861@obsidianresearch.com>
 <20130729181607.GM24642@n2100.arm.linux.org.uk>
Message-ID: <20130729184048.GE15861@obsidianresearch.com>
To: linux-arm-kernel@lists.infradead.org
List-Id: linux-arm-kernel.lists.infradead.org

On Mon, Jul 29, 2013 at 07:16:07PM +0100, Russell King - ARM Linux wrote:

> What does it take?  Good practice, care, thought and planning.  All
> the qualities which should already be present for kernel _engineers_.
> Not an "lets create something for me, I don't care about anyone else"
> attitude.

I agree with what you've written, but we are looking at this from
different ends of the problem.

I fully agree you can create a main line kernel GIT tree that has a
stable DT ABI.

However, I as an ODM, with time pressure, cannot wait for the kernel
folks to finish this work. So from my perspective the DT will not be
stable, as I will put whatever interm stuff I choose to have a
shippable product.

Thus I have to design my systems for an unstable DT, and the message
from the kernel community to people in my posistion should be:

  When you ship early with non-mainlined DT schema, design your boot
  system around an unstable DT. Plan to migrate your DT to upstream
  once it becomes finalized.

Here is the rub: Once I design for an unstable DT I simply don't
derive value from the kernel communities work to create a stable DT.

So who is getting the benefit of this work, and is it worth the cost?

Jason